Patterns of left ventricular hypertrophy and geometric remodeling in essential hypertension

The spectrum of left ventricular geometric adaptation to hypertension was investigated in 165 patients with untreated essential hypertension and 125 age- and gender-matched normal adults studied by two-dimensional and M-mode echocardiography. Among hypertensive patients, left ventricular mass index and relative wall thickness were normal in 52%, whereas 13% had increased relative wall thickness with normal ventricular mass ("concentric remodeling"), 27% had increased mass with normal relative wall thickness (eccentric hypertrophy) and only 8% had "typical" hypertensive concentric hypertrophy (increase in both variables). Systemic hemodynamics paralleled ventricular geometry, with the highest peripheral resistance in the groups with concentric remodeling and hypertrophy, whereas cardiac index was super-normal in those with eccentric hypertrophy and low normal in patients with concentric remodeling. The left ventricular short-axis/long-axis ratio was positively related to stroke volume (r = 0.45, p less than 0.001), with cavity shape most elliptic in patients with concentric remodeling and most spheric in those with eccentric hypertrophy. Normality of left ventricular mass in concentric remodeling appeared to reflect offsetting by volume "underload" of the effects of pressure overload, whereas eccentric hypertrophy was associated with concomitant pressure and volume overload. Thus, arterial hypertension is associated with a spectrum of cardiac geometric adaptation matched to systemic hemodynamics and ventricular load. Concentric left ventricular remodeling and eccentric hypertrophy are more common than the typical pattern of concentric hypertrophy in untreated hypertensive patients.

Lumen diameter of normal human coronary arteries. Influence of age, sex, anatomic variation, and left ventricular hypertrophy or dilation

BACKGROUND

Precise knowledge of the expected "normal" lumen diameter at a given coronary anatomic location is a first step toward developing a quantitative estimate of coronary disease severity that could be more useful than the traditional "percent stenosis."

METHODS AND RESULTS

Eighty-three arteriograms were carefully selected from among 9,160 consecutive studies for their smooth lumen borders indicating freedom from atherosclerotic disease. Of these, 60 men and 10 women had no abnormalities of cardiac function, seven men had idiopathic dilated cardiomyopathy, and six men had left ventricular hypertrophy associated with significant aortic stenosis. Lumen diameter was measured at 96 points in 32 defined coronary segments or major branches. Measurements were scaled to the catheter, corrected for imaging distortion, and had a mean repeat measurement error of 0.12 mm. When sex, anatomic dominance, and branch length were accounted for, normal lumen diameter at each of the standard anatomic points could usually be specified with a population variance of +/- 0.6 mm or less (SD) and coefficient of variation of less than 0.25 (SD/mean). For example, the left main artery measured 4.5 +/- 0.5 mm, the proximal left anterior descending coronary artery (LAD) 3.7 +/- 0.4 mm, and the distal LAD 1.9 +/- 0.4 mm. For the LAD, lumen diameter was not affected by anatomic dominance (right versus left), but for the right coronary artery, proximal diameter varied between 3.9 +/- 0.6 and 2.8 +/- 0.5 mm (p less than 0.01) and for the left circumflex, between 3.4 +/- 0.5 and 4.2 +/- 0.6 mm (p less than 0.01). Women had smaller epicardial arterial diameter than men (-9%; p less than 0.001), even after normalization for body surface area (p less than 0.01). Branch artery caliber was unaffected by the anatomic dominance but increased with branch length, expressed as a fraction of the origin-to-apex distance (p less than 0.001). Lumen diameter was not affected by age or by vessel tortuosity but was significantly increased among men with left ventricular hypertrophy (+ 17%; p less than 0.001) or dilated cardiomyopathy (+ 12%; p less than 0.001).

CONCLUSIONS

This is a reference normal data set against which to compare lumen dimensions in various pathological states. It should be of particular value in the investigation of diffuse atherosclerotic disease.

Distribution and correlates of sonographically detected carotid artery disease in the Cardiovascular Health Study. The CHS Collaborative Research Group

BACKGROUND AND PURPOSE

This article describes the prevalence of extracranial carotid atherosclerosis assessed by ultrasonography, its association with risk factors, and its relation to symptomatic coronary disease and stroke in men and women aged > or = 65 years.

METHODS

Maximum percent stenosis, maximum common carotid artery wall thickness, and maximum internal carotid artery wall thickness were assessed using duplex ultrasound in 5,201 men and women aged > or = 65 years in the Cardiovascular Health Study, a study of the risk factors and natural history of cardiovascular disease in the elderly. Existing coronary disease and stroke were assessed by physical examination and participant history.

RESULTS

Detectable carotid stenosis was present in 75% of men and 62% of women, although the prevalence of > or = 50% stenosis was low, 7% in men and 5% in women. Maximum stenosis and maximum wall thickness measurements increased with age and were uniformly greater at all ages in men than in women (p < 0.00001). Established risk factors for atherosclerosis (hypertension, smoking, diabetes) and indications of vascular disease (left ventricular hypertrophy, major electrocardiographic abnormality, bruits, and history of heart disease or stroke) related to all three carotid artery measures in the elderly. Of the three ultrasound measures, the best correlate for a history of coronary disease was maximum internal carotid artery wall thickness. For stroke the best correlate was common carotid artery wall thickness. Multiple logistic regression models of prevalent coronary heart disease and stroke that included the ultrasound findings indicated, after adjustment for age and sex, that maximum internal wall thickness and maximum common carotid wall thickness were significant correlates of both. Maximum stenosis did not add significantly to the correlation.

CONCLUSIONS

In the elderly the incidence of carotid atherosclerosis was high, although the frequency of severe disease was low. The prevalence and severity of carotid atherosclerosis continued to increase with age even in the late decades of life, and more disease was found in men than in women at all ages. Known risk factors for atherosclerosis continued to relate to carotid abnormalities in the later decades of life, both in symptomatic and asymptomatic subjects.

Measurement of left ventricular wall thickness and mass by echocardiography

Echocardiographic measurements of minor axis and wall thickness and calculations from these two measurements of left ventricular end-diastolic volume and mass were performed in 24 patients and compared with angiocardiographic measurements of the same variables in corresponding patients. The echo-measured left ventricular end-diastolic chamber dimension (D d ) correlated closely with the angiographic minor axis in the AP plane (correlation coefficient 0.87 and se ± 0.45 cm) and with the minor axis from the lateral film (r = 0.91, se ±0.39 cm). Similar correlations were found between measurements by these methods of wall thickness (r = 0.89, se ±1.3 mm), of end-diastolic volume (r = 0.94, se ±30.6 cc), and of left ventricular mass (r = 0.88, se ±49.19 g). The reproducibility of this method was established by independent recordings and measurements of echo Polaroid films by two observers. The percent systolic wall thickening, as determined by echocardiography, identified subjects with ejection fractions greater or less than 0.50. Echocardiography offers a reliable and reproducible method for measuring left ventricular wall thickness and mass. Finally, ultrasound may provide an accurate method for measuring systolic wall thickening in man.

The impact of obesity on left ventricular mass and geometry. The Framingham Heart Study

OBJECTIVE

--To determine the relationship of varying degrees of obesity with left ventricular mass and geometry.

DESIGN

--Survey.

SETTING

--Population-based epidemiologic study.

PARTICIPANTS AND METHODS

--M-mode echocardiograms, which were adequate for estimation of left ventricular mass, were obtained in 3922 healthy participants of the Framingham Heart Study. Measured height and weight were used to calculate body-mass index, a measure of obesity.

RESULTS

--Body-mass index was strongly correlated with left ventricular mass. After adjusting for age and blood pressure, body-mass index remained a strong independent predictor of left ventricular mass, left ventricular wall thickness, and left ventricular internal dimension (P less than .01 for all). Body-mass index was associated with prevalence of echocardiographic left ventricular hypertrophy, particularly in subjects with a body-mass index exceeding 30 kg/m2.

CONCLUSIONS

--Obesity is significantly correlated with left ventricular mass, even after controlling for age and blood pressure. The increase in left ventricular mass associated with increasing adiposity reflects increases in both left ventricular wall thickness and left ventricular internal dimension.

Mitofusin-2 maintains mitochondrial structure and contributes to stress-induced permeability transition in cardiac myocytes

Mitofusin-2 (Mfn-2) is a dynamin-like protein that is involved in the rearrangement of the outer mitochondrial membrane. Research using various experimental systems has shown that Mfn-2 is a mediator of mitochondrial fusion, an evolutionarily conserved process responsible for the surveillance of mitochondrial homeostasis. Here, we find that cardiac myocyte mitochondria lacking Mfn-2 are pleiomorphic and have the propensity to become enlarged. Consistent with an underlying mild mitochondrial dysfunction, Mfn-2-deficient mice display modest cardiac hypertrophy accompanied by slight functional deterioration. The absence of Mfn-2 is associated with a marked delay in mitochondrial permeability transition downstream of Ca(2+) stimulation or due to local generation of reactive oxygen species (ROS). Consequently, Mfn-2-deficient adult cardiomyocytes are protected from a number of cell death-inducing stimuli and Mfn-2 knockout hearts display better recovery following reperfusion injury. We conclude that in cardiac myocytes, Mfn-2 controls mitochondrial morphogenesis and serves to predispose cells to mitochondrial permeability transition and to trigger cell death.

Left atrial diameter as an independent predictor of first clinical cardiovascular events in middle-aged and elderly adults: the Strong Heart Study (SHS)

BACKGROUND

Echocardiographic left atrial (LA) volume has been documented to be an independent predictor of cardiovascular events. Less is known about the predictive ability of anteroposterior LA diameter, a simpler measure of LA size obtained routinely during echocardiographic evaluation.

METHODS

We investigated the prognostic value of LA diameter for incident cardiovascular events in 2804 American Indians free of clinical cardiovascular disease, valvular disease, and atrial fibrillation. Echocardiographic variables were obtained using standardized methods, and previously derived sex-specific partition values were used to define left ventricular (LV) hypertrophy indexed to height(2.7) (in meters) and LA enlargement (> 4.2 cm in men, > 3.8 cm in women). Cardiovascular events included nonfatal stroke, coronary heart disease, congestive heart failure, and fatal cardiovascular disease based on validated definitions.

RESULTS

During a median follow-up of 7 years, 368 events occurred. LA diameter, both as a continuous and as a categorical variable, was significantly associated with incident cardiovascular events in unadjusted analyses. In multivariable analyses that adjusted for age, sex, body mass index, hypertension, diabetes, total cholesterol-high-density lipoprotein cholesterol, smoking, renal insufficiency, LV hypertrophy, abnormal LV systolic and diastolic function, mitral annular calcification, fibrinogen, and C-reactive protein, both LA diameter (risk ratio 1.04/mm, 95% CI 1.02-1.07, P < .002) and LA enlargement (risk ratio 1.57, 95% CI 1.17-2.10, P = .002) remained independent predictors of first cardiovascular events.

CONCLUSIONS

In this population-based cohort, LA diameter independently predicted incident cardiovascular events after adjustment for established clinical, echocardiographic, and inflammatory risk factors. This simple measure of LA dilatation can identify individuals at heightened risk who may warrant more aggressive risk factor modification.

Cardiac hypertrophy is not a required compensatory response to short-term pressure overload

BACKGROUND

Cardiac hypertrophy is considered a necessary compensatory response to sustained elevations of left ventricular (LV) wall stress.

METHODS AND RESULTS

To test this, we inhibited calcineurin with cyclosporine (CsA) in the setting of surgically induced pressure overload in mice and examined in vivo parameters of ventricular volume and function using echocardiography. Normalized heart mass increased 45% by 5 weeks after thoracic aortic banding (TAB; heart weight/body weight, 8.3+/-0.9 mg/g [mean+/-SEM] versus 5. 7+/-0.1 mg/g unbanded, P<0.05). Similar increases were documented in the cell-surface area of isolated LV myocytes. In mice subjected to TAB+CsA treatment, we observed complete inhibition of hypertrophy (heart weight/body weight, 5.2+/-0.3 mg/g at 5 weeks) and myocyte surface area (endocardial and epicardial fractions). The mice tolerated abolition of hypertrophy with no signs of cardiovascular compromise, and 5-week mortality was not different from that of banded mice injected with vehicle (TAB+Veh). Despite abolition of hypertrophy by CsA (LV mass by echo, 83+/-5 mg versus 83+/-2 mg unbanded), chamber size (end-diastolic volume, 33+/-6 microL versus 37+/-1 microL unbanded), and systolic ejection performance (ejection fraction, 97+/-2% versus 97+/-1% unbanded) were normal. LV mass differed significantly in TAB+Veh animals (103+/-5 mg, P<0.05), but chamber volume (end-diastolic volume, 44+/-6 microL), ejection fraction (92+/-2%), and transstenotic pressure gradients (70+/-14 mm Hg in TAB+Veh versus 77+/-11 mm Hg in TAB+CsA) were not different.

CONCLUSIONS

In this experimental setting, calcineurin blockade with CsA prevented LV hypertrophy due to pressure overload. TAB mice treated with CsA maintain normal LV size and systolic function.

Small artery remodeling is the most prevalent (earliest?) form of target organ damage in mild essential hypertension

BACKGROUND

The heart and blood vessels are exposed to elevated blood pressure (BP) in hypertensive patients, but their changes in response to BP or non-hemodynamic stimuli may be different, and occur with different time-courses. To evaluate this, we studied the prevalence of structural and functional alterations of resistance arteries and cardiac hypertrophy in patients with mild essential hypertension.

METHODS

Resistance arteries were dissected from gluteal subcutaneous tissue from 38 hypertensive patients (47 +/- 1 years; 71% male; BP 148 +/- 2/99 +/- mmHg), studied on a pressurized myograph, and compared to those from 10 normotensives (44 +/- 3 years; 40% male; BP 113 +/- 4/76 +/- 2 mmHg).

RESULTS

The prevalence of abnormal structure (media-to-lumen ratio, M/L) and impaired endothelial function (maximal acetylcholine response) was 97 and 58% (abnormal was defined as greater than mean + 1 SD of normotensives), or 63 and 34% (abnormal defined as greater than mean +/- 2SD). Thirty four percent of hypertensive patients exhibited left ventricular hypertrophy by echocardiography. When grouped into tertiles according to increasing ambulatory systolic BP (SBP), the highest BP tertile showed increased M/L (P< 0.01) and left ventricular mass index (LVMI, P < 0.05) and marginally decreased endothelial function (P= 0.07). LVMI was greatest in the tertile of patients with highest M/L (P< 0.05). Endothelial function was decreased in the tertile with greatest vascular stiffness (P< 0.01). By multivariate analysis, M/L correlated with ambulatory SBP (beta = 0.40, P= 0.02), and LVMI correlated with ambulatory SBP (beta = 0.41, P = 0.001) and body mass index (beta = 0.30, P< 0.05). Female sex influenced endothelial function negatively (beta = -0.63, P< 0.01).

CONCLUSION

Structural alterations of resistance arteries were demonstrated in most hypertensive patients, followed by endothelial dysfunction and cardiac hypertrophy in a smaller number of hypertensives. Small artery structural remodeling may precede most clinically relevant manifestations of target organ damage in mild essential hypertension.

Cardiac hypertrophy, aortic compliance, peripheral resistance, and wave reflection in end-stage renal disease. Comparative effects of ACE inhibition and calcium channel blockade

BACKGROUND

We wished to assess the respective roles of the antihypertensive and blood pressure (BP)-independent effects of antihypertensive drugs on arterial hemodynamics and left ventricular hypertrophy (LVH) in end-stage renal disease (ESRD) patients.

METHODS AND RESULTS

In a double-blind study, 24 ESRD patients with LVH were randomized to 12 months' administration of either the angiotensin-converting enzyme (ACE) inhibitor perindopril (n = 14) or the calcium channel blocker nitrendipine (n = 10). Repeated measurements of the following parameters were performed: BP (mercury sphygmomanometry), left ventricular mass (LVM, echocardiography), cardiac output (aortic cross-section and velocity integral), total peripheral resistance (cardiac output and mean BP), aortic and large-artery compliance (pulse wave velocity, Doppler flowmeter), and arterial wave reflections (augmentation index, applanation tonometry). Radioimmunoassay was used to determine plasma renin activity, aldosterone, and plasma catecholamine levels. Two-way (time-treatment) ANOVA for repeated measures was used for statistical analysis. Perindopril and nitrendipine induced significant and similar decreases in BP, total peripheral resistance (P < .001), aortic and arterial pulse wave velocities (P < .001), and arterial wave reflections (P < .01). At baseline, the two groups had LVH mostly due to increased LV end-diastolic diameter (LVEDD) (perindopril, 54.3 +/- 1.4 and nitrendipine, 54.3 +/ 2.4 mm) with near-normal mean LV wall thickness (perindopril, 11.4 +/- 0.3 and nitrendipine, 11.2 +/- 0.4 mm). A decrease in LVM was observed only in patients receiving perindopril (from 317 +/- 18 to 247 +/- 21 g) (time-treatment interaction, P = .036). Nitrendipine had no significant effect on LVM (314 +/- 29 versus 286 +/- 32 g). The decrease in LVM observed with perindopril was associated with a reduction in LVEDD (49.9 +/- 1.6 versus 54.3 +/- 1.4 mm after 12 months) (time-treatment interaction, P = .04), while the mean LV wall thickness was unchanged (11.4 +/- 0.3 versus 10.5 +/- 0.5 mm). Cardiac alterations were not correlated with changes in BP or with alterations in plasma renin activity or aldosterone or catecholamine levels.

CONCLUSIONS

In ESRD patients with LVH, ACE inhibition decreases LVM independently of its antihypertensive effect and of associated alterations in arterial hemodynamics. The decrease in LVM was due primarily to a decrease in LV volume, which may have resulted in these patients from chronic volume overload.

Left ventricular midwall mechanics in systemic arterial hypertension. Myocardial function is depressed in pressure-overload hypertrophy

BACKGROUND

Left ventricular (LV) midwall geometry has been described conventionally as the sum of the chamber radius and half of the wall thickness; this convention is based on the assumption of uniform transmural thickening during systole. However, theoretical considerations and experimental data indicate that the inner half (inner shell) of the LV wall thickens more than the outer half (outer shell). Thus, an end-diastolic circumferential midwall fiber exhibits a relative migration toward the epicardium during systole. As a result, the conventional method provides an overestimate of the extent of the midwall fiber shortening.

METHODS AND RESULTS

We developed an ellipsoidal model with a concentric two-shell geometry (nonuniform thickening) to assess midwall fiber length transients throughout the cardiac cycle. This modified midwall method was used in the analysis of LV cineangiograms from 15 patients with systemic arterial hypertension and 14 normal subjects. Study groups were classified according to LV mass index (LVMI): 14 normal subjects (group I), eight hypertensive patients with a normal LVMI (group II), and seven hypertensive patients with an increased LVMI (group III). There were no significant differences in LV end-diastolic pressure or volume among the three groups; the ejection fraction was slightly greater in group II (70 +/- 5%) than in groups I (65 +/- 8%) and III (66 +/- 4%), but this trend did not achieve statistical significance. Values for endocardial and conventional midwall fractional shortening (FS) were also similar in the three groups. By contrast, FS by the concentric two-shell geometry (modified midwall method) in group III (16 +/- 2%) was significantly less than that seen in groups I and II (21 +/- 4% and 21 +/- 5%, respectively; both p less than 0.05). This difference achieves greater importance when it is recognized that mean systolic circumferential stress was lower in group III (151 +/- 22 g/cm2) than in groups I and II (244 +/- 37 g/cm2 and 213 +/- 38 g/cm2, respectively; both p less than 0.01). The midwall stress-shortening coordinates in six of the seven group III patients were outside the 95% confidence limits for the normal (group I) subjects. Thus, despite a normal ejection fraction, systolic function is subnormal in hypertensive patients with LV hypertrophy.

CONCLUSIONS

Chamber dynamics provide an overestimate of myocardial function, especially when LV wall thickness is increased. This is due to a relatively greater contribution of inner shell thickening in pressure-overload hypertrophy.

Left ventricular remodeling in the year after first anterior myocardial infarction: a quantitative analysis of contractile segment lengths and ventricular shape

Infarct expansion after myocardial infarction results in early ventricular enlargement and distortion of ventricular geometry. To characterize the components of late volume enlargement, biplane left ventriculography was performed in 52 patients 3 weeks and 1 year after a first anterior myocardial infarction. Biplane diastolic circumference and contractile and noncontractile segment lengths were measured. Global geometry was evaluated by using a sphericity index (angiographic volume of the ventricle divided by the volume of a sphere with the same circumference). Regional geometry was assessed by measurement of endocardial curvature, an important determinant of wall tension. End-diastolic volume was enlarged at baseline and increased at 1 year (230 +/- 42 to 244 +/- 55 ml, p = 0.01) as a result of increases in contractile segment length (34 +/- 5 to 37 +/- 5 cm, p less than 0.001) and sphericity index (0.74 +/- 0.07 to 0.76 +/- 0.08, p less than 0.001), whereas the noncontractile segment length decreased (15 +/- 6 to 12 +/- 6 cm, p less than 0.005). Curvature analysis revealed a flattening of presumably high tension concavity at the anterobasal (-6.0 +/- 4.0 to -4.5 +/- 3.7, p less than 0.01) and inferior (-4.5 +/- 2.0 to -3.6 +/- 2.1, p less than 0.005) margins of the infarct and less bulging of the anterior wall (9.4 +/- 2.5 to 8.2 +/- 2.3, p less than 0.001). Patients selected for late enlargement (diastolic volume increase greater than 20 ml, n = 19) had an increase in sphericity (0.75 +/- 0.05 to 0.80 +/- 0.08, p less than 0.005) and in diastolic circumference (54 +/- 3 to 56 +/- 4 cm, p less than 0.001) secondary to elongation of the contractile segment (32 +/- 4 to 36 +/- 4 cm, p = 0.001) at 1 year. Thus, late ventricular enlargement after anterior infarction results from an increase in contractile segment length and a change in ventricular geometry and is not a result of progressive infarct expansion. In the group of patients at high risk for late ventricular enlargement because of persistent occlusion of the infarct-related vessel, captopril therapy attenuated late volume enlargement by preventing these changes in contractile segment length and chamber geometry.

Changes in left ventricular anatomy and function in hypertension and primary aldosteronism

We investigated the effects on the heart of hypertension due to the excess of aldosterone and suppression of the renin-angiotensin system caused by primary aldosteronism with M-mode echocardiography and transmitral Doppler flow velocity measurements. We studied 34 consecutive patients with primary aldosteronism and 34 with essential hypertension individually matched for age, gender, race, body mass index, blood pressure values, and duration of hypertension. The groups were similar in age, body mass index, blood pressure, and duration of hypertension. However, lower serum potassium levels (3.5 +/- 0.6 versus 4.1 +/- 0.2 mmol/L, P < .0001) and plasma renin activity (0.53 +/- 0.45 versus 1.82 +/- 1.59 ng Ang I x mL-1 x h-1, P < .0001) and higher plasma aldosterone levels (1107 +/- 774 versus 206 +/- 99 pmol/L, P < .0001), left ventricular wall thickness, and left ventricular mass index (112 +/- 4.7 versus 98 +/- 3.7 g/m2, P = .029) were found in patients with primary aldosteronism compared with those with essential hypertension. Similarly, the PQ interval was longer (173 +/- 20 versus 141 +/- 14 milliseconds, P < .001) in primary aldosteronism than in essential hypertension patients. Significantly more primary aldosteronism than essential hypertension patients had left ventricular hypertrophy or left ventricular concentric remodeling (50% versus 15%, chi 2 = 11.97, P = .007). Both the E wave flow velocity integral (1063 +/- 65 versus 1323 +/- 78, P = .013) and the E/A integral ratio (0.91 +/- 0.05 versus 1.25 +/- 0.08, P < .001) were lower, and atrial contribution to left ventricular filling was higher (53.3 +/- 1.5% versus 45.5 +/- 1.3% P < .001) in patients with primary aldosteronism compared with essential hypertension patients. After 1 year of follow-up, highly significant decreases of left ventricular wall thickness and mass were observed in patients treated with surgical excision of an aldosterone-producing tumor, but not in those with medical therapy. Thus, in patients with primary aldosteronism, the excess aldosterone with suppression of the renin-angiotensin system is associated with both increased left ventricular mass and significant changes of left ventricular diastolic filling. The former changes appear to be reversible on removal of the cause of excessive aldosterone production.

Cardiac tamponade in medical patients

We reviewed the cases of 56 medical patients wih cardiac tamponade who were treated at the University of Cincinnati. A paradoxic arterial pulse was critical in the diagnosis because most patients did not have a small quiet heart, and blood pressure was often well maintained. Fifty-two of 55 patients had enlarged cardiac silhouette by chest radiogram; heart sounds were diminished in 19 patients; arterial systolic pressure was greater than or equal to 100 mm Hg in 35, and arterial pulse pressure was greater than or equal to 40 mm Hg in 27. Echocardiograms in 23 patients showed abnormally increased right ventricular dimensions and decreased left ventricular dimensions during inspiration, except in one patient with left ventricular dysfunction. The causes of cardiac tamponade were metastatic tumor in 18 patients, idiopathic pericarditis in eight and uremia in five; five cases of tamponade occurred after heparin administration in acute cardiac infarction. Myxedema and dissecting aneurysm each caused tamponade in two patients. Pericardiocentesis relieved tamponade initially in 40 of 46 patients; however, two suffered fatal complications. Pericardial resection was done in 18, including 12 of these 46.

Rapid ventricular filling in left ventricular hypertrophy: II. Pathologic hypertrophy

To define the extent of left ventricular ejection and filling abnormalities in patients with mild hypertension, a non-imaging nuclear probe was used to generate high resolution time-activity curves in 25 patients with an average systolic blood pressure of 154 +/- 20 mm Hg and diastolic pressure of 98 +/- 8 mm Hg. The hypertensive patients did not meet electrocardiographic criteria for left ventricular hypertrophy, and none had evidence of ischemic or other cardiac disease. Compared with 25 age-matched normal subjects who had average systolic and diastolic pressures of 123 +/- 10 and 79 +/- 8 mm Hg, respectively, the hypertensive patients had a significantly lower ejection rate (2.00 +/- 0.20 versus 2.34 +/- 0.36 end-diastolic counts/s for the control group, p less than 0.05) and ejection fraction (58 +/- 4.9 versus 62 +/- 4.4) (p less than 0.05). The hypertensive patients had a markedly lower average rapid left ventricular filling rate (1.87 +/- 0.32 versus 2.69 +/- 0.41 counts/s for the control group, p less than 0.001). Although there was a modest inverse relation between echocardiographic left ventricular mass index and filling rate in the hypertensive patients (r = -0.59, p less than 0.01), 4 of 12 hypertensive patients with normal left ventricular mass index had a depressed filling rate. All of the hypertensive patients with increased left ventricular mass index had an abnormal left ventricular filling rate (less than 1.89 end-diastolic counts/s).(ABSTRACT TRUNCATED AT 250 WORDS)

Left atrial size and the risk of ischemic stroke in an ethnically mixed population

BACKGROUND AND PURPOSE

The association between left atrial size and ischemic stroke is controversial and has been suggested to exist only in men and to be mediated by left ventricular mass. Data are available almost exclusively for white patients. The purpose of this study was to evaluate the association between left atrial size and ischemic stroke in a multiethnic population.

METHODS

A population-based case-control study was conducted in 352 patients aged >39 years with first ischemic stroke and in 369 age-, gender-, and race-ethnicity-matched community controls. Left atrial diameter was measured by 2-dimensional transthoracic echocardiography and indexed by body surface area. Conditional logistic regression analysis was performed to assess the risk of stroke associated with left atrial index in the overall group and in the age, gender, and race-ethnic strata after adjustment for the presence of other stroke risk factors.

RESULTS

Left atrial index was associated with ischemic stroke in the overall group (adjusted OR 1.47 per 10 mm/1.7 m(2) of body surface area; 95% CI 1.03 to 2.11). The association was present in men (adjusted OR 2.81, 95% CI 1.42 to 5.57) but not in women (adjusted OR 1.08, 95% CI 0.70 to 1.66), and in patients aged <60 years (adjusted OR 3.78, 95% CI 1.36 to 10.54) but not >60 years (adjusted OR 1.23, 95% CI 0.84 to 1.81). Subgroup analyses showed the risk to be present in men across all age subgroups. In women, the lack of association between left atrial index and stroke was most strongly influenced by left ventricular hypertrophy. A trend toward an association between left atrial index and stroke was observed in whites (adjusted OR 1.81, 95% CI 0.81 to 4.09) and Hispanics (adjusted OR 1.61, 95% CI 0.98 to 2.65) but was less evident in blacks (adjusted OR 1.25, 95% CI 0.74 to 2.14).

CONCLUSIONS

Left atrial enlargement is associated with an increased risk of ischemic stroke after adjustment for other stroke risk factors, including left ventricular hypertrophy. The association is observed in men of all ages, whereas in women it is attenuated by other factors, especially left ventricular hypertrophy. Interracial differences in the stroke risk may exist that need further investigation.

Serial echocardiographic-Doppler assessment of left ventricular geometry and function in rats with pressure-overload hypertrophy. Chronic angiotensin-converting enzyme inhibition attenuates the transition to heart failure

BACKGROUND

Although chronic pressure overload may progress to left ventricular (LV) failure, the pathophysiology of this transition is not well understood. In addition, the effects of chronic angiotensin-converting enzyme (ACE) inhibition on this transition are largely undefined.

METHODS AND RESULTS

To examine changes in LV structure and function during the transition to heart failure, rats with LV hypertrophy due to banding of the ascending aorta (LVH, n = 22) and age-matched sham-operated rats (n = 6) were studied 6, 12, and 18 weeks after aortic banding. Two-dimensionally guided transthoracic M-mode echocardiograms and transmitral Doppler spectra were recorded for assessment of LV geometry and systolic and diastolic functions. LVH rats were randomized to no treatment (n = 10) or treatment with the ACE inhibitor fosinopril (50 mg/kg per day, n = 12) after the baseline echocardiogram. Six weeks after banding, LVH rats had increased LV wall thickness with normal cavity dimensions and supranormal endocardial systolic shortening. However, midwall shortening was mildly depressed, and a restrictive diastolic filling pattern was present. After 18 weeks of untreated pressure overload, LV wall thickness was unchanged, but cavity dilation, a fall in endocardial shortening, and further deterioration of diastolic filling were evident. In contrast to untreated LVH rats, the fosinopril-treated rats showed no change in LV diastolic cavity dimension, and systolic and diastolic functions did not deteriorate or improved. Closed chest LV systolic pressures at 18 weeks were not different in LVH or LVH-fosinopril rats (197 versus 198 mm Hg), although end-diastolic pressure was higher in the untreated rats (18 versus 11 mm Hg). Calculated LV systolic wall stress was lower in fosinopril-treated than untreated LVH rats. The severity of LV diastolic filling abnormalities correlated strongly with operating LV chamber stiffness (r = .88, P < .0001).

CONCLUSIONS

This model of pressure overload is characterized initially by concentric LV hypertrophy with compensated LV chamber performance; however, markedly abnormal diastolic filling is present. The transition from compensated hypertrophy to early failure is heralded by LV dilation, impairment of systolic function, and progression of the abnormalities in LV filling. Chronic ACE inhibition in rats with supravalvular aortic banding (1) does not change in vivo LV systolic pressure but prevents increased LV cavity size and increased LV wall stress and (2) attenuates impairment of (or improves) both systolic and diastolic functions. The effects of fosinopril could be explained in part by inhibition of an intracardiac renin-angiotensin system.

Mineralocorticoid receptor antagonism attenuates cardiac hypertrophy and failure in low-aldosterone hypertensive rats

Chronic elevation of plasma aldosterone contributes to heart failure. Mineralocorticoid receptor (MR) antagonism is cardioprotective in such a setting, but whether such protection occurs in the presence of low-aldosterone concentrations remains unclear. We investigated whether MR blockade attenuates cardiac hypertrophy and failure in rats with salt-sensitive hypertension. Dahl salt-sensitive (DS) rats fed a high-salt diet from 7 weeks develop concentric left ventricular (LV) hypertrophy secondary to hypertension at 12 weeks followed by heart failure at 19 weeks (DS-CHF). DS rats on such a diet were treated with a non-antihypertensive dose of the selective MR antagonist eplerenone from 12 to 19 weeks. Renin activity and aldosterone concentration in plasma were decreased in DS-CHF rats compared with controls. LV hypertrophy and fibrosis, as well as macrophage infiltration around coronary vessels, were apparent in DS-CHF rats. The amounts of mRNAs for 11beta-hydroxysteroid dehydrogenase type 1, MR, monocyte chemoattractant protein 1, and osteopontin were increased in these hearts. Treatment of DS-CHF rats with eplerenone inhibited these changes in gene expression, as well as coronary vascular inflammation and heart failure. Eplerenone attenuated both the decrease in the ratio of reduced to oxidized glutathione and the increase in NADPH oxidase activity apparent in DS-CHF rat hearts. MR blockade with eplerenone thus resulted in attenuation of LV hypertrophy and failure, without an antihypertensive effect, in rats with low-aldosterone hypertension. The beneficial cardiac effects of eplerenone are likely attributable, at least in part, to attenuation of myocardial oxidative stress and coronary vascular inflammation induced by glucocorticoid-activated MRs.

Calcification of the mitral annulus: etiology, clinical associations, complications and therapy

This report reviews the clinical features of 80 patients with roentgenographically proved mitral annular calcification. The mean age of the group was 73 years, and there was a 2.5 to 1 female to male ratio. Evaluation for underlying cardiovascular disease revealed six patients with severe calcific valvular aortic stenosis; five patients with hypertrophic cardiomyopathy, 11 with mitral prolapse and 33 with significant arterial hypertension (blood pressure greater or equal to 150/96 mm Hg). Eighty-five per cent of the group (68 of 80 patients) had an underlying cardiac disorder associated with either chronically increased left ventricular systolic pressure or abnormal leaflet motion. Other cardiovascular abnormalities occurring as complications secondary to the mitral ring calcification included subacute bacterial endocarditis (three cases), arterial emboli (five episodes) and high grade atrioventricular block (16 cases). Twelve patients had severe mitral regurgitation; successful mitral valve replacement was carried out in four patients (all with myxomatous mitral tissue). Evidence of diffuse conduction system disease, not limited to the area of the cardiac fibrous skeleton, was found frequently (44 patients). Nine patients had sinus node dysfunction and 35 patients had electrocardiographic evidence of distal intraventricular (fascicular) block. Twenty-one patients eventually required pacemakers for management of symptomatic bradyarrhythmias. Atrial fibrillation was present in 23 patients. In this review it was found that calcification of the mitral annulus is frequently associated with or induces serious cardiovascular disease. Since some of these disorders may be modified by appropriate therapy, calcification of the mitral annulus should no longer be ignored as a benign marker of the elderly heart.

Left ventricular hypertrophy independent of hypertension in patients with obstructive sleep apnoea

To evaluate cardiac structure and function as well as blood pressure in the obstructive sleep apnoea syndrome (OSAS), we investigated 61 male patients and 61 male controls with M-mode and two-dimensional echocardiography. All patients had a history of habitual snoring and a diagnosed light to severe OSAS by previous investigations of nocturnal oxygen saturation status. No subject in the control group had a history of OSAS or hypertension. Body weight was higher in the OSAS patients than in the controls (P less than 0.001). Fifty per cent (31 out of 61) of the OSAS patients had systemic hypertension; 17 of these 31 were on pharmacological antihypertensive treatment. Neither the systolic nor the diastolic blood pressures were found to correlate to the severity of the OSAS (desaturation index). The heart rate was higher at rest in the OSAS patients with or without systemic hypertension compared to the controls with or without a blood pressure level above 165/95 mmHg (P less than 0.05 and P less than 0.01, respectively). Left ventricular (LV) internal dimensions as assessed by echocardiography did not differ between the two groups, while the interventricular septum and the LV posterior wall were thicker in the OSAS group. Thus, the LV mass and the LV mass index were significantly higher among the OSAS patients (P less than 0.001 and P less than 0.001). The LV mass index was approximately 15% higher among the 30 normotensive OSAS patients with no history of cardiac disease compared with the normotensive controls (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical, radiographic, and hemodynamic correlations in chronic congestive heart failure: conflicting results may lead to inappropriate care

PURPOSE

Clinical and radiographic examinations are commonly used for estimating severity and titrating therapy of chronic congestive heart failure. The purpose of this study was to establish the relationship between findings on history, physical examination, chest roentgenogram, and pulmonary capillary wedge pressure (PCWP).

PATIENTS AND METHODS

Fifty-two consecutive patients with chronic congestive heart failure, referred for evaluation for heart transplantation, were studied; all patients underwent history, physical examination, upright chest roentgenogram, and cardiac catheterization. The mean left ventricular ejection fraction was 0.19 +/- 0.06. Patients were divided into three groups according to their PCWP: Group 1, normal PCWP (less than or equal to 15 mm Hg, n = 19); Group 2, mild to moderately elevated PCWP (16 to 29 mm Hg, n = 15); Group 3, markedly elevated PCWP (greater than or equal to 30 mm Hg, n = 18).

RESULTS

Physical and radiographic signs of congestion were more common in the groups with higher PCWP, but they could not be used to reliably separate patients with different filling pressures. Physical findings (orthopnea, edema, rales, third heart sound, elevated jugular venous pressure) or radiographic signs (cardiomegaly, vascular redistribution, and interstitial and alveolar edema) had poor predictive value for identifying patients with PCWP values greater than or equal to 30 mm Hg. These findings had poor negative predictive value to exclude significantly elevated PCWP (greater than 20 mm Hg). Radiographic pulmonary congestion was absent in eight (53%) patients in Group 2 and seven (39%) in Group 3. In patients in Group 2 and 3, those without radiographic congestion were in a better New York Heart Association functional class (3.5 +/- 0.5 versus 2.8 +/- 0.6, p less than 0.01). There was good correlation between right atrial pressure and PCWP (r = 0.64, p less than 0.001). A normal right atrial pressure had no predictive value, but a pressure greater than 10 mm Hg was seen in all but one patient with a PCWP value greater than 20 mm Hg.

CONCLUSION

Clinical, radiographic, and hemodynamic evaluations of chronic congestive heart failure yield conflicting results. Absence of radiographic or physical signs of congestion does not ensure normal PCWP values and may lead to inaccurate diagnosis and inadequate therapy. It is not known whether therapy aimed at normalizing PCWP is superior to relieving clinical and radiographic signs of congestion.

Aliskiren, a human renin inhibitor, ameliorates cardiac and renal damage in double-transgenic rats

We tested the hypothesis that the renin inhibitor aliskiren ameliorates organ damage in rats transgenic for human renin and angiotensinogen genes (double transgenic rat [dTGR]). Six-week-old dTGR were matched by albuminuria (2 mg per day) and divided into 5 groups. Untreated dTGR were compared with aliskiren (3 and 0.3 mg/kg per day)-treated and valsartan (Val; 10 and 1 mg/kg per day)-treated rats. Treatment was from week 6 through week 9. At week 6, all groups had elevated systolic blood pressure (BP). Untreated dTGR showed increased BP (202+/-4 mm Hg), serum creatinine, and albuminuria (34+/-5.7 mg per day) at week 7. At week 9, both doses of aliskiren lowered BP (115+/-6 and 139+/-5 mm Hg) and albuminuria (0.4+/-0.1 and 1.6+/-0.6 mg per day) and normalized serum creatinine. Although high-dose Val lowered BP (148+/-4 mm Hg) and albuminuria (2.1+/-0.7 mg per day), low-dose Val reduced BP (182+/-3 mm Hg) and albuminuria (24+/-3.8 mg per day) to a lesser extent. Mortality was 100% in untreated dTGR and 26% in Val (1 mg/kg per day) treated rats, whereas in all other groups, survival was 100%. dTGR treated with low-dose Val had cardiac hypertrophy (4.4+/-0.1 mg/g), increased left ventricular (LV) wall thickness, and diastolic dysfunction. LV atrial natriuretic peptide and beta-myosin heavy chain mRNA, albuminuria, fibrosis, and cell infiltration were also increased. In contrast, both aliskiren doses and the high-dose Val lowered BP to a similar extent and more effectively than low-dose Val. We conclude that in dTGR, equieffective antihypertensive doses of Val or aliskiren attenuated end-organ damage. Thus, renin inhibition compares favorably to angiotensin receptor blockade in reversing organ damage in dTGR.